tiny.chant.preprocess.system

1pub const system = @import("system.zig");

1const std = @import("std");2const sys = @import("sys");3const types = @import("types.zig");45const Error = types.Error;6const Options = types.Options;7const Prepared = types.Prepared;89pub fn run(10    arena: std.mem.Allocator,11    environ: std.process.Environ,12    source_path: []const u8,13    source_dir: []const u8,14    from_temporary: bool,15    options: Options,16    diagnostic: ?*types.Diagnostic,17) Error![]const u8 {18    var argv = std.ArrayListUnmanaged([]const u8).empty;19    defer argv.deinit(arena);20    try argv.appendSlice(arena, &.{ "cc", "-std=c2x", "-E", "-nostdinc" });21    if (from_temporary) {22        try argv.append(arena, "-iquote");23        try argv.append(arena, source_dir);24    }25    for (options.include_dirs) |dir| {26        try argv.append(arena, "-I");27        try argv.append(arena, dir);28    }29    for (options.defines) |define| {30        try argv.append(arena, "-D");31        try argv.append(arena, define);32    }33    try argv.append(arena, source_path);3435    var io_state = std.Io.Threaded.init(arena, .{ .environ = environ });36    defer io_state.deinit();3738    const result = sys.process.run(arena, io_state.io(), .{39        .argv = argv.items,40        .stdout_limit = .limited(16 * 1024 * 1024),41        .stderr_limit = .limited(256 * 1024),42    }) catch |err| switch (err) {43        error.FileNotFound => return error.PreprocessorUnavailable,44        error.OutOfMemory => return error.OutOfMemory,45        else => {46            recordFailure(diagnostic, source_path, @errorName(err));47            return error.PreprocessFailed;48        },49    };50    switch (result.term) {51        .exited => |code| if (code != 0) {52            recordFailure(diagnostic, source_path, failureText(result.stderr, result.stdout));53            return error.PreprocessFailed;54        },55        else => {56            recordFailure(diagnostic, source_path, failureText(result.stderr, result.stdout));57            return error.PreprocessFailed;58        },59    }60    return result.stdout;61}6263const failure_text_limit = 512;6465fn recordFailure(diagnostic: ?*types.Diagnostic, source_path: []const u8, message: []const u8) void {66    const out = diagnostic orelse return;67    out.* = .{ .message = message, .file = source_path };68}6970fn failureText(stderr: []const u8, stdout: []const u8) []const u8 {71    const text = if (std.mem.trim(u8, stderr, " \t\r\n").len != 0) stderr else stdout;72    const trimmed = std.mem.trim(u8, text, " \t\r\n");73    return trimmed[0..@min(trimmed.len, failure_text_limit)];74}7576pub fn writeTemporary(arena: std.mem.Allocator, source: []const u8) Error!Prepared {77    const path = try std.fmt.allocPrint(arena, "/tmp/chant-preprocess-{d}.c", .{sys.time.nanoTimestamp()});78    sys.fs.writeFile(path, source) catch return error.PreprocessFailed;79    return .{ .path = path, .temporary = true };80}8182test "preprocess failure carries the compiler stderr" {83    var arena_state = std.heap.ArenaAllocator.init(std.testing.allocator);84    defer arena_state.deinit();85    const arena = arena_state.allocator();8687    const source_path = "/tmp/chant-preprocess-diagnostic.c";88    sys.fs.writeFile(source_path,89        \\#include <chant-no-such-header.h>90        \\int x;91        \\92    ) catch return;9394    var diagnostic: types.Diagnostic = .{};95    const failed = run(arena, sys.env.current(), source_path, "/tmp", false, .{}, &diagnostic);96    if (failed) |_| {97        return error.TestUnexpectedResult;98    } else |err| switch (err) {99        error.PreprocessorUnavailable => return,100        error.PreprocessFailed => {101            try std.testing.expect(diagnostic.message.len != 0);102            try std.testing.expect(std.mem.indexOf(u8, diagnostic.message, "chant-no-such-header.h") != null);103            try std.testing.expectEqualStrings(source_path, diagnostic.file);104        },105        else => return err,106    }107}108109test "failure text prefers stderr and bounds the excerpt" {110    try std.testing.expectEqualStrings("fatal error", failureText("  fatal error\n", "ignored"));111    try std.testing.expectEqualStrings("stdout text", failureText("   \n", "stdout text\n"));112    const long = @as([((failure_text_limit + 64)) * ("e").len]u8, @bitCast(@as([(failure_text_limit + 64)][("e").len]u8, @splat(("e")[0..("e").len].*))));113    try std.testing.expectEqual(failure_text_limit, failureText(&long, "").len);114}